Vaginal brachytherapy for postoperative endometrial cancer: 2014 Survey of the American Brachytherapy Society

Intermediate-risk endometrial cancer treated with adjuvant brachytherapy using single dosimetric planning: long-term outcome and toxicity assessment

OBJECTIVE

Brachytherapy of the vaginal dome is the recommended adjuvant treatment for intermediate-risk endometrial cancer. This study assessed the results of dosimetric planning of high-dose-rate brachytherapy exclusively in the first treatment session.

STUDY DESIGN

This retrospective study included all patients who underwent hysterectomy for endometrial cancer followed by adjuvant brachytherapy of the vaginal dome between 2012 and 2015. Local recurrence rates, overall survival (OS) rates, recurrence-free survival (RFS) rates, and related acute and late toxicity rates were evaluated.

RESULTS

This analysis included 250 patients, of whom 208 were considered to be at high-intermediate risk of disease recurrence. After a median follow-up of 56 months, the cumulative incidence of local recurrence was 4.8% at 3 years [95% confidence interval (CI) 2.8-8.3] and 7.8% at 5 years (95% CI 4.8-12.6). The 5-year OS rate was 86.2% (95% CI 80.6-90.3), and the 5-year RFS rate was 77.5% (95% CI 71.1-82.7). Acute toxicity occurred in 20 (8%) patients, of which two patients had grade ≥3 toxicity. Only one patient (0.4%) presented with late grade ≥3 toxicity.

CONCLUSION

These findings confirm the tolerability of this brachytherapy approach, indicating minimal cases of late grade ≥3 toxicity, associated with a good 5-year OS rate. With the advent of molecular prognostic factors, the current focus revolves around discerning those individuals who gain the greatest benefit from adjuvant therapy, and tailoring treatment more effectively.

Risk-Tailoring Radiotherapy for Endometrial Cancer: A Narrative Review

Endometrial cancer is the most common gynecologic cancer in the United States and it contributes to the second most gynecologic cancer-related deaths. With upfront surgery, the specific characteristics of both the patient and tumor allow for risk-tailored treatment algorithms including adjuvant radiotherapy and systemic therapy. In this narrative review, we discuss the current radiation treatment paradigm for endometrial cancer with an emphasis on various radiotherapy modalities, techniques, and dosing regimens. We then elaborate on how to tailor radiotherapy treatment courses in combination with other cancer-directed treatments, including chemotherapy and immunotherapy. In conclusion, this review summarizes ongoing research that aims to further individualize radiotherapy regimens for individuals in an attempt to improve patient outcomes.

Isolated vaginal recurrence in women with stage I endometrial cancer

OBJECTIVE

To compare clinical and pathologic characteristics of women with surgical stage I endometrial carcinoma by location of first recurrence and describe characteristics of isolated vaginal recurrence.

METHODS

Patients with 2009 International Federation of Obstetrics and Gynecology (FIGO) stage I endometrial carcinoma treated at two large cancer centers from 1/1/2009-12/31/2017 were identified. Sarcoma histology was excluded. Recurrences were grouped into isolated vaginal or extravaginal. Isolated vaginal recurrences were localized by anatomic location within the vaginal vault. Clinical and pathologic variables were compared with chi-square analysis, and Kaplan-Meier curves with log-rank tests.

RESULTS

Of 2815 women identified, 278 (10%) experienced a recurrence. Sixty-one patients (2%) had an isolated vaginal recurrence, including 42 (69%) at the vaginal apex; 217 (8%) had an extravaginal recurrence, including 18 with a vaginal component. Median time to recurrence was 11 months (range, 1-68) for isolated vaginal recurrence and 20 months (range, 1-98) for extravaginal recurrence (P < .004). Of 960 patients (34%) treated with adjuvant vaginal brachytherapy (VBT), 156 (16%) recurred; 19 (2%) had an isolated vaginal recurrence, including 16 (84%) at the vaginal apex. Three-year PFS rates for isolated vaginal recurrence were 97.6% (SE ± 0.4%) with minimally invasive surgery (MIS) versus 96.9% (SE ± 1.1%) with open (P = .8), and for extravaginal recurrence were 91.8% (SE ± 0.7%) with MIS versus 90.8% (SE ± 1.8%) with open (P = .8).

CONCLUSIONS

Isolated vaginal recurrences in stage I endometrial cancer are detected earlier than non-vaginal recurrences. Surgical approach does not appear to impact recurrence. Adjuvant VBT after primary surgery carries a 1%-2% risk of isolated vaginal apex recurrence.

Are 7.5 Gy×2 fractions more efficient than 6 Gy×3 in exclusive postoperative endometrial cancer brachytherapy? A clinical and dosimetrical analysis

PURPOSE

To compare two vaginal brachytherapy (VBT) schedules in postoperative endometrial carcinoma (PEC) patients considering vaginal-cuff relapses (VCR), late toxicities, dosimetry analysis and vaginal dilator use.

MATERIAL AND METHODS

110 PEC patients were treated with exclusive high-dose-rate VBT using two schedules. Group-1:44-patients received 6 Gy×3fractions (September-2011-April-2014); Group-2:66-patients were treated with 7.5 Gy×2fractions with a dose limit of equivalent total doses in 2-Gy fr (EQD2(α/β=3)) of 68 Gy in the most exposed 2 cm3 of clinical target volume (CTV) (July-2015-November-2021). The dose was prescribed at 5 mm from the applicator surface. Were evaluated the overall radiation dose delivered to 90% of the CTV (D90), the CTV receiving 100% of the prescription dose (V100) and the EQD2(α/β=3) received in the most exposed 2 cm3 to dose in CTV. Late toxicity was prospectively assessed using RTOG scores for bladder and rectum and objective LENT-SOMA criteria for late vaginal toxicity (LVT).

STATISTICS

Descriptive analysis, Chi-square, Student's t-tests and Kaplan and Meier method.

RESULTS

The median follow-up was 60 months (15.9-60). There were no VCR or late toxicities in bladder or rectum. LVT ≥ G1 appeared in 26/44 (59.1%) in Group-1 and 25/66 (37.9%) in Group-2. The mean EQD2(α/β=3) received by the most exposed 2 cm3 of CTV was 63.7 Gy ± 10.0 in Group-1 and 60.5 Gy ± 3.8 in Group-2 (p = 0.063). There were no differences in adherence to vaginal dilator use ≥9 months, overall D90 and V100.

CONCLUSION

Considering the lack of vaginal relapses and similar LVT over time, 7.5 Gy×2fractions seem more efficient in terms of patient comfort, workload, and cost. This is the first study using dosimetry parameters to compare effectivity of schedules. Larger series are needed to confirm the present results.

Dosimetric Evaluation of Organs at Risk From SAVE Protocol

PURPOSE

The objective of this work was to evaluate dosimetric characteristics to organs at risk (OARs) from short-course adjuvant vaginal cuff brachytherapy (VCB) in early endometrial cancer compared with standard of care (SOC) in a multi-institutional prospective randomized trial.

METHODS AND MATERIALS

SAVE (Short Course Adjuvant Vaginal Brachytherapy in Early Endometrial Cancer Compared to Standard of Care) is a prospective, phase 3, multisite randomized trial in which 108 patients requiring VCB were randomized to an experimental short-course arm (11 Gy × 2 fractions [fx] to surface) and SOC arm. Those randomized to the SOC arm were subdivided into treatment groups based on treating physician discretion as follows: 7 Gy × 3 fx to 5 mm, 5 to 5.5 Gy × 4 fx to 5 mm, and 6 Gy × 5 fx to surface. To evaluate doses to OARs of each SAVE cohort, the rectum, bladder, sigmoid, small bowel, and urethra were contoured on planning computed tomography, and doses to OARs were compared by treatment arm. Absolute doses for each OAR and from each fractionation scheme were converted to 2 Gy equivalent dose (EQD23). Each SOC arm was compared with the experimental arm separately using 1-way analysis of variance, followed by pairwise comparisons using Tukey's honestly significant difference test.

RESULTS

The experimental arm had significantly lower doses for rectum, bladder, sigmoid, and urethra compared with the 7 Gy × 3 and 5 to 5.5 Gy × 4 fractionation schemes; however, the experimental arm did not differ from the 6 Gy × 5 fractionation scheme. For small bowel doses, none of the SOC fractionation schemes were statistically different than the experimental. The highest EQD23 doses to the examined OARs were observed to come from the most common dose fractionation scheme of 7 Gy × 3 fx. With a short median follow-up of 1 year, there have been no isolated vaginal recurrences.

CONCLUSIONS

Experimental short-course VCB of 11 Gy × 2 fx to the surface provides a comparable biologically effective dose to SOC courses. Experimental short-course VCB was found to reduce or be comparable to D2cc and D0.1cc EQD23 doses to rectum, bladder, sigmoid, small bowel, and urethra critical structures. This may translate into a comparable or lower rate of acute and late adverse effects.

Partial-Length Treatment With Brachytherapy in Patients With Endometrial Cancer With High-Risk Features Is as Effective as Full-Length Vaginal Brachytherapy but With Reduced Toxicity

PURPOSE

Full-length vaginal (FLV) brachytherapy for patients with endometrial cancer and high-risk features should be considered as per the American Brachytherapy Society to reduce distal vaginal recurrence in patients with endometrial cancers with papillary serous/clear cell histologies, grade 3 status, or extensive lymphovascular invasion. We sought to investigate this patient population and report outcomes of treatment with high-dose-rate (HDR) brachytherapy in women treated with FLV brachytherapy versus partial-length vaginal (PLV) brachytherapy.

METHODS AND MATERIALS

With institutional review board approval, we identified patients with endometrial cancer meeting American Brachytherapy Society criteria of high-risk features treated with adjuvant HDR between 2004 and 2010. HDR doses were 21Gy in 3 fractions delivered to either the full-length or partial-length vagina. Acute and late toxicities were evaluated using the Radiation Therapy Oncology Group scale and Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer grading, respectfully. Vaginal recurrences were assessed by physical examination and pap smears. Statistical analyses were performed using SPSS version 23 software.

RESULTS

Of 240 patients treated with HDR brachytherapy, 121 were treated with FLV brachytherapy, and 119, with PLV brachytherapy. The median follow-up was 9.5 years (range, 8-11 years) for FLV patients and 8.5 years (range, 7-10 years) for PLV patients; 0% of patients had vaginal recurrences, and 1.4% and 0.9% had proximal vaginal recurrences, respectively (P = .54). All patients treated with FLV brachytherapy developed grade 3 mucositis of the lower vagina/introitus (P < .0001) and had increased analgesics use compared with those treated with PLV brachytherapy (P < .0001). In total, 23% of patients treated with FLV brachytherapy developed grade 3 stenosis of the lower vagina/introitus, in contrast to 0% of patients treated with PLV brachytherapy (P < .0001).

CONCLUSIONS

PLV brachytherapy is as effective as FLV brachytherapy in reducing local recurrence and causes a significantly lower incidence of acute and late toxicities. The results of this study caution radiation oncologists regarding the careful use of FLV brachytherapy in patients with endometrial cancer and high-risk features.

Practice patterns of adjuvant radiotherapy in women with stage I to II endometrial carcinoma: a real-world multi-institutional analysis in China

BACKGROUND

This study aimed to report clinical practice patterns of postoperative radiotherapy for stage I to II endometrial carcinoma (EC) patients treated in 13 Chinese medical centers.

METHODS

We included early stage EC patients treated by hysterectomy and adjuvant RT between 2003 and 2017 from 13 institutions. Patients were classified into 4 risk groups based on ESMO-ESGO-ESTRO recommendations (2014).

RESULTS

A total of 1,227 cases were analyzed. Along the 15 years of the study, an increasing tendency was found towards administration for vaginal brachytherapy (VBT) alone, while the proportion of external beam pelvic radiotherapy (EBRT) alone remained stable in the corresponding period. When radiation modalities were stratified by risk groups, proportion of VBT alone significantly increased in all risk groups. The higher the risk, the later VBT became the main adjuvant treatment modality. However, EBRT alone or with VBT remained the main adjuvant method for high-risk patients. There were 13 dose-fractionation schemes for VBT alone with the scheme of 30 Gy in 6 fractions prescribed at 0.5cm under the vaginal mucosa accounting for most. There were 17 schemes for VBT boost and the most common schedule was 10 Gy in 2 fractions. The upper 3-5cm part of vagina was the most frequent target. 89.6% of the practitioners performed two-dimensional VBT technique. The median dose for EBRT was 50 Gy. From 2003 to 2017, conventional radiotherapy was gradually replaced by three-dimensional conformal radiotherapy modality and intensity modulated radiotherapy.

CONCLUSION

We report a significant shift from EBRT to VBT alone for high-intermediate-risk, intermediate-risk and low-risk EC patients from 2003 to 2017 while EBRT remained the main radiation modality for high-risk early stage patients. There has been remarkable heterogeneity among VBT dose fractionation schedules across China.

TRIAL REGISTRATION

The clinical trial ID was ChiCTR-PRC-17010712. It was authorized by the Institutional Review Board of Peking Union Medical College Hospital (N0. S-K139).

Personalized Brachytherapy for a Herlyn-Werner-Wunderlich Syndrome Patient with Endometrial Cancer: A Case Report

Purpose

Endometrial carcinoma (EC) is a common gynecological malignancy. Vaginal cuff brachytherapy (VBT) is an adjuvant treatment for EC. Since a single-channel cylinder sometimes delivers inadequate dose coverage to the vaginal apex, three-dimensional (3D) printing technology can be used to achieve satisfactory dose distribution. Here, we report the first case of an EC patient with Herlyn-Werner-Wunderlich syndrome (HWWS) treated with VBT using 3D-printed applicators.

Case Presentation

Here, we present a case study of an endometrial cancer patient with HWWS who underwent surgery. During adjuvant radiotherapy, 3D-printed applicators were used in VBT. To accomplish the reconstruction of the source pathways on magnetic resonance imaging, catheters with copper sulfate were placed in two 3D-printed applicators. The early tolerance of this treatment was positive. During the 6-month follow-up, locoregional recurrence was not detected.

Conclusion

Our findings strongly indicate that VBT with 3D-printed applicators may be a reasonable treatment option for EC with HWWS.

(Potential) mishaps of high dose rate vaginal cuff brachytherapy

PURPOSE

Considering how commonly vaginal cuff brachytherapy is used, there is relatively little literature regarding the potential, albeit low, risk for complications. We present here three potentially serious mishaps, involving cylinder misplacement, dehiscence, and excessive normal tissue irradiation due to unique anatomy.

METHODS

Three patients with potentially serious treatment errors were encountered in the authors' usual clinical practice. Each patient's records were reviewed for this report.

RESULTS

For patient #1, CT simulation revealed grossly inadequate cylinder insertion, most obvious on the sagittal view. For patient #2, CT simulation revealed that the cylinder extended beyond the perforated vaginal cuff and was surrounded by bowel. For patient #3, CT images were used only to verify cylinder depth. A standard library plan, based on cylinder diameter and active length was used. In retrospect, the images revealed an unusually thin rectovaginal septum, with the lateral and posterior vaginal wall thickness estimated to be less than 2 mm. Her fractional normal tissue doses were calculated for this report, revealing a rectal Dmax (per fraction) of 10.8 Gy, D2.0 of 7.4 Gy, and a V100 of 2.8 cc. All doses were far in excess of those anticipated for a minimal 0.5 cm vaginal wall depth.

CONCLUSION

Vaginal cuff HDR brachytherapy is a high volume, routine procedure. Even in experienced hands, however, it carries a risk of improper cylinder placement, cuff dehiscence, and excessive normal tissue dose, all of which could seriously impact outcomes. These potential mishaps would be better appreciated and avoided with more extensive use of CT-based quality assurance measures.

Embracing a future of progress in gynecologic brachytherapy

In the last 20 years, gynecologic brachytherapy has made tremendous advancements, most prominently evidenced by the evolution of cervical cancer brachytherapy. In its 20 year history, Brachytherapy has become known as a journal of science, education, and advocacy for our specialty and for our patients. In this review, we celebrate the 25 most impactful manuscripts in gynecologic brachytherapy in the journal's history.

Radiation Therapy for Endometrial Cancer: An American Society for Radiation Oncology Clinical Practice Guideline

PURPOSE

With the results of several recently published clinical trials, this guideline informs on the use of adjuvant radiation therapy (RT) and systemic therapy in the treatment of endometrial cancer. Updated evidence-based recommendations provide indications for adjuvant RT and the associated techniques, the utilization and sequencing of adjuvant systemic therapies, and the effect of surgical staging techniques and molecular tumor profiling.

METHODS

The American Society for Radiation Oncology convened a multidisciplinary task force to address 6 key questions that focused on the adjuvant management of patients with endometrial cancer. The key questions emphasized the (1) indications for adjuvant RT, (2) RT techniques, target volumes, dose fractionation, and treatment planning aims, (3) indications for systemic therapy, (4) sequencing of systemic therapy with RT, (5) effect of lymph node assessment on utilization of adjuvant therapy, and (6) effect of molecular tumor profiling on utilization of adjuvant therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for quality of evidence grading and strength of recommendation.

RESULTS

The task force recommends RT (either vaginal brachytherapy or external beam RT) be given based on the patient's clinical-pathologic risk factors to reduce risk of vaginal and/or pelvic recurrence. When external beam RT is delivered, intensity modulated RT with daily image guided RT is recommended to reduce acute and late toxicity. Chemotherapy is recommended for patients with International Federation of Gynecology and Obstetrics (FIGO) stage I to II with high-risk histologies and those with FIGO stage III to IVA with any histology. When sequencing chemotherapy and RT, there is no prospective data to support an optimal sequence. Sentinel lymph node mapping is recommended over pelvic lymphadenectomy for surgical nodal staging. Data on sentinel lymph node pathologic ultrastaging status supports that patients with isolated tumor cells be treated as node negative and adjuvant therapy based on uterine risk factors and patients with micrometastases be treated as node positive. The available data on molecular characterization of endometrial cancer are compelling and should be increasingly considered when making recommendations for adjuvant therapy.

CONCLUSIONS

These recommendations guide evidence-based best clinical practices on the use of adjuvant therapy for endometrial cancer.

Vaginal cuff brachytherapy for endometrial cancer: a review of major clinical trials with a focus on fractionation

The use of vaginal cuff brachytherapy in the adjuvant management of endometrial cancer has increased over time. Recommendations from the American Brachytherapy Society, American Society of Radiation Oncology, and European Society for Medical Oncology help to guide the application of vaginal cuff brachytherapy. However, wide variation in practice remains regarding treatment techniques. This article reviews the use of vaginal cuff brachytherapy in the post-operative management of endometrial cancer. It covers risk stratification, treatment rationale, outcomes, and treatment planning recommendations with a specific focus on dose-fractionation regimens. The authors performed a thorough literature review of articles pertinent to the goals of this review. Also presented are early results of the Short Course Adjuvant Vaginal Cuff Brachytherapy in Early Endometrial Cancer Compared with Standard of Care (SAVE) trial of a two-fraction vaginal cuff brachytherapy regimen.

Adjuvant vaginal cuff brachytherapy for early-stage endometrial cancer results in excellent disease control with minimal toxicity. The PORTEC-2 trial showed that vaginal cuff brachytherapy is non-inferior to external beam radiation for vaginal recurrence in patients at high-intermediate risk. Vaginal cuff brachytherapy may also be used as a boost following external beam radiation in combination with chemotherapy for high-risk histologies. Numerous techniques can be used for vaginal cuff brachytherapy, including various medical devices, dose-fractionation schedules, and treatment planning approaches. The early control results of the SAVE trial are promising and we are hopeful that this trial establishes two fraction regimens as a viable option for vaginal cuff brachytherapy.

EROS 2.0 study: evaluation of two interventional radiotherapy (brachytherapy) schedules for endometrial cancer: a comparison of late vaginal toxicity rates

BACKGROUND

To compare the late toxicity rates after two different high dose rate (HDR) adjuvant intravaginal interventional radiotherapy (IRT-brachytherapy) dose schedules in stage I-II endometrial cancer.

METHODS

Stage I-II patients with endometrial cancer treated with surgery (with or without lymphadenectomy) and adjuvant HDR-IRT between 2014 and 2020 were included in this analysis. Patients were treated with two schedules. In the first cohort (C1), 21 Gy were delivered in three weekly fractions (7 Gy) prescribed 0.5 cm from the applicator surface. In the second cohort (C2), 24 Gy were delivered in four weekly fractions (6 Gy). The clinical target volume was the upper third of the vagina for C1 and the upper 3 cm for C2. HDR-IRT technique and point prescription (5 mm depth from the applicator surface) were the same for all patients. Vaginal toxicity was scored according to the CTCAE 5.0 scale in terms of the presence versus absence of any toxicity grade. The correlation among toxicity and clinical covariates (age, lymphadenectomy, fractionation, stage) was tested by Pearson correlation test (univariate) and by logistic regression (multivariable).

RESULTS

114 stage I and three stage II patients, median age 62 (range: 32-85) years, were included in this analysis. The mean follow-up was 56.3 months in C1 (40-76) and 20 months in C2 (8-42). Vaginal late toxicity was recorded in 40 and 15 patients in C1 and 2, respectively. Age, lymphadenectomy, and fractionation were significantly correlated with toxicity at univariate analysis (p value = 0.029, 0.006, and 0.002, respectively), while stepwise logistic regression confirmed only age and fractionation as significantly correlated parameters (p value = 0.02 and 0.001, respectively). Three-year local relapse-free, distant metastasis-free and cause-specific survival rates were 96.6%, 94.8%, and 99.1%, respectively.

CONCLUSIONS

This analysis showed lower vaginal late toxicity rate in C2 compared to C1.

Efficacy and safety of a 3D-printed applicator for vaginal brachytherapy in patients with central pelvic-recurrent cervical cancer after primary hysterectomy

PURPOSE

Intracavitary and/or interstitial brachytherapy is an integral component of the management of patients with central pelvic-recurrent cervical cancer after primary hysterectomy, and is typically delivered using conventional applicators. We investigated the efficacy and safety of three-dimensional (3D)-printed, customizable applicators for those patients.

METHODS AND MATERIALS

Twenty-six patients were treated with combination external beam radiotherapy and brachytherapy. Patients with lesions ≤1 and >1 cm before brachytherapy were treated with intracavitary and interstitial brachytherapy, respectively. Dosimetric plans were compared between the vaginal cylinder and 3D-printed applicator for the first 9 patients. Outcomes and treatment-related complications were also investigated.

RESULTS

The median tumor size before brachytherapy was 0.81 cm. Intracavitary, interstitial, and combined interstitial-intracavitary brachytherapy were performed in 22 (85%), 3 (11%), and 1 (4%) of the patients, respectively. The clinical target volume (CTV) coverage goal was achieved with all 3D-printed plans but failed with three single-channel cylinder plans (33.3%). Owing to 3D-printed transvaginal applicator guidance, there was no need to adjust the needle position after implantation. The mean CTV dose for all patients was 71 ± 8.2 Gy; all met the dose constraints to the organs at risk, but 1 (4%) had a rectal D_2cc overdose. The 2-year local control, progression-free survival, and overall survival rates were 87.8%, 71.0%, and 91.6%, respectively. Four patients (21%) developed early grade 3-4 hematological toxicities and 1 (4%) developed a late grade 3 adverse event.

CONCLUSIONS

High-quality intracavitary and/or interstitial brachytherapy can be achieved using a 3D-printed applicator and yields favorable outcomes with acceptable toxicity.

Toxicity and Efficacy After Adjuvant Vaginal Brachytherapy Using 30 Gy in 6 Fractions for Stages I and II Endometrial Cancer

Purpose

This study aimed to evaluate outcomes and toxicity in patients with endometrial cancer per our institutional adjuvant vaginal cuff brachytherapy (VBT) fractionation scheme.

Methods and Materials

We identified women with International Federation of Gynecology and Oncology stages I and II endometrial cancer who underwent surgical staging and adjuvant high-dose-rate VBT without external beam radiation. All patients received 30 Gy in 6 fractions to the upper one-third of the vagina, prescribed to a depth of 5 mm and delivered twice weekly. Toxicities were prospectively elicited at each follow up, and rates of recurrence and survival were retrospectively assessed.

Results

We identified 247 eligible patients treated between 1992 and 2018 with a median follow up of 5.8 years (range, 0.1-24.7 years). Most patients had stage I disease (52% stage IA; 37% stage IB), and 11% of patients were stage II. Deep myometrial invasion was predictive of local recurrence (P = .002). The 5-year rates of local recurrence, regional recurrence, and distant metastases were 5%, 5%, and 7%, respectively. Five-year overall and disease-free survival were 91% and 83%, respectively. The most common grade 1 toxicities were acute fatigue (11% crude rate), urinary frequency (11%), chronic (>6 months) urinary frequency (13%), urinary incontinence (13%), and vaginal stenosis (21%). There were few grade 2 toxicities (all <5%) and no grade 3 to 5 toxicities.

Conclusions

The adjuvant VBT fractionation scheme of 30 Gy in 6 fractions results in low rates of toxicity, with no grade ≥3 adverse events, and local control rates comparable with those from other published series using different fractionation schemes.

Preliminary results of a vaginal constraint for reducing G2 late vaginal complications after postoperative brachytherapy in endometrial cancer: a prospective analysis

Purpose

To evaluate the preliminary results of the use of 68 Gy EQD2_{(α/β=3 Gy)} as a dose limit to the lowest dose in the most exposed 2 cm³ of the vagina in order to reduce G2 late vaginal problems in postoperative endometrial carcinoma (EC).

Methods

From November 2016 to October 2019, 69 postoperative EC patients receiving vaginal brachytherapy (VBT) ± external beam radiotherapy (EBRT) were prospectively analyzed. The median EBRT dose was 45 Gy (range: 44–50.4 Gy), 1.8−2 Gy/day, 5 fractions(Fr)/week. VBT was administered with the following schedule: 1Fr of 7 Gy after EBRT and 2 daily Fr × 7.5 Gy in exclusive VBT. The dose was prescribed at 0.5 cm from the applicator surface with an active length of 2.5 cm; 56 patients were treated with vaginal cylinders (49–3.5 cm, 6–3 cm, and 1–2.5 cm) and 13 with the colpostat technique. The overall VBT dose was adjusted to meet the vaginal restriction of < 68 Gy EQD2_{(α/β=3 Gy)} at 2 cm³. Late toxicity was prospectively assessed using RTOG scores for bladder and rectum, and the objective LENT-SOMA criteria for vagina.

Results

With a median follow-up of 31.0 months, no vaginal-cuff recurrences were found. Late toxicity: only 1G1(1.4%) rectal toxicity; 21G1(30.4%) and 3G2(4.3%) vaginal complications. Only one (1.4%) of 3 G2 manifested as vaginal shortening.

Conclusions

In postoperative EC patients treated with VBT, only one developed G2 vaginal stenosis with the use of 68 Gy EQD2_{(α/β=3 Gy)} as a dose constraint. These preliminary results seem to indicate the value of this dose limit for reducing G2 vaginal stenosis. Nonetheless, these findings should be confirmed in a larger number of patients with longer follow-up.

A comparison between 2D and 3D planning of high-dose-rate vaginal cuff brachytherapy in patients with stage I-II endometrial cancer using cobalt-60

Purpose

Post-surgery radiation can reduce the risk of loco-regional relapse in high-intermediate-risk endometrial cancer. High-dose-rate vaginal cuff brachytherapy (HDR-BRT) is an acceptable method of radiation in majority of endometrial cancer cases. Although 2D planning is frequently used for treatment based on physical examination without any imaging, measurement of the dose received by organs-at-risk (OARs) is not possible. Therefore, the present study was the first to compare dose delivered to target and OARs in 2D vs. 3D planning in patients treated with cobalt-60 source.

Material and methods

In this study, organs including vagina wall, bladder, rectum, and sigmoid were contoured on computed tomography (CT) scan images of 37 endometrial cancer patients, and doses delivered to organs were recorded. Statistics, such as D₉₀, D₉₉, V₁₀₀, V₁₅₀, V₂₀₀, D_0.1cc, D_1cc, and D_2cc were determined.

Results

D₉₀ and D₉₉ were lower in 3D treatment planning in comparison with 2D. Although V₁₀₀ was more in 3D planning, V₁₅₀ and V₂₀₀ were less. Analyzing D_0.1cc, D_1cc, and D_2cc of OARs revealed that doses given to rectum, sigmoid, and bladder were less in 3D planning compared to 2D.

Conclusions

Comparison of 2D and 3D planning results showed that 3D planning could deliver an appropriate dose to the target while sparing more OARs.

ACR-ABS-ASTRO practice parameter for the performance of radionuclide-based high-dose-rate brachytherapy

PURPOSE

This practice parameter aims to detail the processes, qualifications of personnel, patient selection, equipment, patient and personnel safety, documentation, and quality control and improvement necessary for an HDR brachytherapy program.

METHODS AND MATERIALS

This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American Brachytherapy Society (ABS), and the American Society for Radiation Oncology (ASTRO).

RESULTS

Brachytherapy is a radiotherapeutic modality in which radionuclide or electronic sources are used to deliver a radiation dose at a distance of up to a few centimeters by surface, intracavitary, intraluminal, or interstitial application. Brachytherapy alone or combined with external beam radiotherapy plays an important role in the management and treatment of patients with cancer. High-dose-rate (HDR) brachytherapy uses radionuclides, such as iridium-192, at dose rates of ≥12 Gy/hr to a designated target point or volume, and it is an important treatment for a variety of malignant and benign conditions. Its use allows for application of high doses of radiation to defined target volumes with relative sparing of adjacent critical structures.

CONCLUSIONS

HDR brachytherapy requires detailed attention to personnel, equipment, patient and personnel safety, and continuing staff education. Coordination between the radiation oncologist and treatment planning staff and effective quality assurance procedures are important components of successful HDR brachytherapy programs.

Vaginal cuff brachytherapy: do we need to treat to more than a two-centimeter active length?

PURPOSE

American Brachytherapy Society (ABS) guidelines recommend using a 3-5 cm active length (AL) when treating vaginal cuff (VC) in adjuvant setting of endometrial cancer (EC). The purpose of this study was to evaluate local control and toxicity, using an AL of 1 or 2 cm and immobilization with a traditional table-mounted (stand) or patient-mounted (suspenders) device.

MATERIAL AND METHODS

Between 2005 and 2019, 247 patients with EC were treated with adjuvant high-dose-rate vaginal cuff (HDR-VC) brachytherapy with or without external beam radiation (EBRT). Treatment was prescribed to a 0.5 cm depth, with an AL of 1 or 2 cm, using stand or suspenders. VC boost after EBRT was typically administered with 2 fractions of 5.5 Gy, while VC brachytherapy alone was typically applied with 3 fractions of 7 Gy or 5 fractions of 5.5 Gy.

RESULTS

The combination of suspender immobilization and an AL of 2 cm (n = 126, 51%) resulted in 5-year local control of 100%. An AL of 2 cm compared to 1 cm correlated with better local control (99.1% vs. 88.5%, p = 0.0479). Regarding immobilization, suspenders correlated with improved local control compared to stand (100% vs. 86.7%, p = 0.0038). Immobilization technique was significantly correlated with AL (p < 0.0001). Only 5 (2.0%) patients experienced grade ≥ 3 toxicity, all of whom received EBRT.

CONCLUSIONS

In the present series, an AL of 2 cm provided excellent local control, while 1 cm was inadequate. Suspender immobilization was a practical alternative to stand immobilization in HDR brachytherapy of the vaginal cuff.

Vaginal cuff brachytherapy practice in endometrial cancer patients: a report from the Turkish Oncology Group

Purpose

The American Brachytherapy Association is attempting to develop standards for delivering brachytherapy, although differences in practice have been reported in the literature. This study evaluated vaginal cuff brachytherapy (VBT) practice and quality of life-related recommendations among Turkish radiation oncologists.

Material and methods

A nationwide web-based 17-item survey was distributed to the members of the Turkish Society for Radiation Oncology. These members received e-mail notifications, and a link was posted on the Turkish Society for Radiation Oncology internet site to solicit voluntary responses The survey addressed the simulation processes, target volume, prescribed dose, delivery schedules, and recommendations related to vaginal side effects.

Results

Fifty-seven radiation oncologists responded to the survey. The most used dose fraction schemes for adjuvant VBT were 7 Gy × 3 fractions (30%), 5.5 Gy × 5 fractions (26%), and 6 Gy × 5 fractions (28%). The preferred VBT scheme was 5 Gy × 3 fractions (50%) when the external beam radiotherapy (EBRT) dose was 45 Gy external radiotherapy, while the preferred schemes were 6 Gy × 3 fractions (30%) or 5 Gy × 3 fractions (32%) when the external radiotherapy dose was increased to 50.4 Gy. One-half of the respondents delivered VBT twice a week, and the dose was prescribed to 0.5 cm from vaginal mucosa by 86% of the respondents. There was no common definition for the dose prescription length, which was defined as 3 cm from the vaginal cuff in 33% of responses and as 4 cm in 35% of responses. For serous and clear cell histological types, 38% of the respondents targeted "full cylinder length". To prevent vaginal side effects, 78% of the respondents recommended using a vaginal dilator and/or sexual intercourse after VBT.

Conclusions

This survey revealed variations in the clinical practice of VBT among Turkish radiation oncologists, which suggests that standardization is necessary.

Impact of CT-based planning and bladder volume changes on the dosimetry of vaginal vault brachytherapy

Aim:

To compare dose to target and organs at risk (OARs) in conventional plan (2D) versus computed tomography (CT)-based three-dimensional (3D) plan in vaginal cuff brachytherapy (VBT) and to compare the effect of bladder distension on target and OARs dosimetry.

Materials and methods:

Post-hysterectomy patients with an indication for VBT were included in the study. All patients underwent planning CT scans with a full bladder and an empty bladder protocol. For each CT, two plans were generated—one library-based 2D plan and another CT-based 3D plan. Dosimetric parameters were recorded for clinical target volume (CTV) and OARs.

Results:

A total of 92 observations were made from data collected from 46 patients. Difference between CTV dose in terms of 2D and 3D plans were not statistically significant for CTV (p = 0·11). Significant reduction in D0·1cc, D1cc and D2cc dose parameters were observed in bladder, rectum, sigmoid and bowel doses with the 3D plan (p < 0·001). Bladder distension showed a 20% reduction in dose for bowel (p < 0·001). Bladder distension also showed a 6·12% (p = 0·047) increase in D2cc, but there was a significant reduction in the mean dose to the bladder.

Conclusion:

Our study demonstrates the dosimetric benefits with 3D CT-based planning for VBT over 2D-based conventional planning and benefit of bladder distension in the reduction of bowel dose without compromising dose to the target volume.

Adjuvant vaginal cuff brachytherapy: dosimetric comparison of conventional versus 3-dimensional planning in endometrial cancer

PURPOSE

To evaluate dosimetric differences between point-based 2-dimensional (2D) vaginal brachytherapy (VBT) treatment planning technique and volume-based 3-dimensional (3D) VBT method for endometrial cancer (EC).

MATERIAL AND METHODS

Ten patients with uterine-confined EC treated with VBT were included in this study. All patients received 27.5 Gy in 5 fractions. Three different treatment plans were performed for each patient: plan A for dose prescribed to the entire vaginal wall thickness delineated via computed tomography guidance, plan B for dose prescribed to the vaginal mucosa/cylinder surface, and plan C for dose prescribed to 5 mm beyond the vaginal mucosa/cylinder surface. Dose-volume histograms (DVH) of treatment volumes and organs at risk (OARs) were evaluated and compared.

RESULTS

DVH analysis of target volume doses (D100, D95, and D90) showed a significant difference between plan A and plan B (p = 0.005), and plan B was found lower. D100 for plan C was significantly higher than plan A (p = 0.009), but for D95 and D90, no statistically significant difference was found (p = 0.028 and p = 0.028, respectively). In terms of OARs doses, including vagina, rectum, bladder, and sigmoid, D2cm3 doses were significantly higher in plan A than plan B (p = 0.009, p = 0.009, p = 0.005, and p = 0.005, respectively). All these doses were also significantly lower than in plan C (p = 0.005, p = 0.012, and p = 0.013, respectively), except for sigmoid (p = 0.155).

CONCLUSIONS

In this dosimetric analysis, we have shown that the volume-based 3D VBT technique provides the ability to balance the target dose against the sparing of OARs. Therefore, in the new modern 3D treatment era, instead of normalization of the dose to standard reference points, customized 3D volume-based VBT planning should be recommended.

Adjuvant electronic brachytherapy for endometrial carcinoma: A 4-year outcomes report

PURPOSE

The purpose of the study was to report the outcomes of a single-center adjuvant electronic brachytherapy (e-BT) experience for patients with endometrial carcinoma.

METHODS AND MATERIALS

Patients were retrospectively assessed. Intracavitary e-BT was applied through a cylindrical applicator (diameters 2.5-3.5 cm). e-BT single doses ranged between 4 and 7 Gy (EQD2 ∼ 6-12, α/β of 10 Gy and an relative biological effectiveness of 1.3) at 5-mm depth. Adverse events are reported at first week, 1-3 months, 3-12 months, 12-24 months, and >24 months. The overall survival, disease-free survival, distant disease control rate, and local control rate were estimated using the Kaplan-Meier method.

RESULTS

Twenty-nine patients were assessed. The median age was 68 [48-86] years. External beam radiotherapy was added in n = 8 (27.6%) patients. Staging was 13.8% for T1a, 51.7% for T1b, 24.1% for T2, 6.9% for T3a, and 3.4% for T3b. Grading was G3 in 51.7% (n = 15), G2 in 20.7% (n = 6), and G1 in 27.6% (n = 8). Median followup was 47 months [5-88]. Overall Grade 1, 2, and 3 toxicity was 89.7% (n = 26), 17.2% (n = 5), and 6.9% (n = 2), respectively. No Grade 3 cystitis or proctitis or any Grade 4 or 5 toxicity occurred during followup. No local recurrences were detected. Estimated distant disease control rate was 92.1% (n = 2, distant metastasis at 7 and 11 months). Estimated 4-year overall survival was 84.8% (n = 4 events, two unrelated to disease) and disease-free survival was 84.6%.

CONCLUSIONS

Our data suggest that e-BT resembles a very-low-toxicity profile and a high local control rate in the adjuvant scenario for patients with endometrial carcinoma.

Efficacy and toxicity of postoperative external beam radiotherapy or chemoradiation for early-stage cervical cancer

OBJECTIVE

The aim of this study was to assess the impact of the evolving role of the addition of chemotherapy to postoperative radiotherapy on oncological outcomes and toxicity in patients with early-stage cervical cancer after radical hysterectomy.

METHODS

Retrospective cohort study of patients with stage IB1-IIB FIGO 2009 cervical cancer treated from November 1999 to May 2015 by primary surgery and radiotherapy (46-50.4 Gy in 1.8-2.0 Gy fractions) with or without concurrent cisplatin (40 mg/m², 5-6 weekly cycles) with or without a brachytherapy boost. Chemotherapy was allocated depending on the risk factors for recurrence. Incidences of all outcomes were calculated using Kaplan-Meier's methodology and compared by log-rank tests. Risk factors for recurrence and survival were identified using Cox's proportional hazards models.

RESULTS

A total of 154 patients were included, median follow-up was 9.6 years (IQR: 6.1-12.8). Five-year pelvic recurrence-free survival was 75.3%; 74.7% in patients with high-risk factors treated with radiotherapy; and 77.3% in those treated with chemoradiation (P=0.43). Distant metastasis-free survival at 5 years was 63.4%; 63.6% in high-risk patients after radiotherapy; and 57.1% after chemoradiation (P=0.36). Five-year overall survival was 63.9%: 66.8% and 51.6% after radiotherapy and after chemoradiation in patients with high-risk factors (P=0.37), respectively. Large tumor size was a risk factor for vaginal and pelvic recurrence, ≥2 involved lymph nodes was a significant risk factor for para-aortic recurrence and death. Mild treatment-related late toxicity was observed in 53.9% of the patients. Five-year severe (grade 3-5) late rectal, bladder, bowel, and vaginal toxicities were, respectively, 1.3%, 0%, 3.4%, and 0.9%. Any late severe toxicity was observed in 5.5% of patients treated with radiotherapy and in 15.3% of those treated with chemoradiation (P=0.07).

CONCLUSION

Postoperative (chemo)radiation for early-stage cervical cancer patients with risk factors for recurrence yields adequate pelvic tumor control, but overall survival is limited due to distant metastasis.

Outcomes of intermediate-risk to high-risk stage I endometrial cancer: 10-year clinical experiences of using in-house multi-channel applicators in a single center

BACKGROUND

There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China. We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage I EC using in-house made multi-channel applicators (IH-MCA) in a single institution.

METHODS

Three hundred and ninety patients with stage I IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015. All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after external beam radiotherapy (EBRT). The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT. Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment. The Kaplan-Meier method was used to calculate survival rate.

RESULTS

Follow-up rate was 92.8% and the median follow-up time was 48 months (range 4-172 months). The 5-year overall survival (OS), progression-free survival, local recurrence, and distant metastasis rates for all patients were 96.3%, 92.1%, 2.9%, and 4.8% respectively. Two patients had isolated relapse in vagina outside the irradiated volume. The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio: 0.368, 95% confidence interval [CI]: 0.131-1.035, P = 0.048; hazard ratio: 0.576, 95% CI: 0.347-0.958, P = 0.026,).

CONCLUSIONS

For patients with IR to HR stage I EC, adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates. Age and grade were the prognostic factors correlated with OS.

Is one brachytherapy fraction of 7 Gy similar to more fractions after external beam irradiation in postoperative endometrial carcinoma?

PURPOSE

To determine whether brachytherapy with a single hypofractionated dose of 7 Gy provides the similar vaginal-cuff relapses and safety profile in terms of complications compared to schedules of 2 or 3 fractions of lower doses in patients treated previously with external beam irradiation in postoperative endometrial carcinoma.

METHODS/MATERIAL

From June 2003 to December 2016, 325 patients were treated with 3 different schedules of high-dose-rate brachytherapy after external beam irradiation for postoperative endometrial carcinoma. The patients were divided into 3 groups: Group-1: 125 patients were treated with 3 fractions of 4-6 Gy per fraction (3 fractions/week) between 2003 and 2008; Group-2: 93 patients were treated with 2 consecutive daily fractions of 5-6 Gy between 2008 and 2011; Group-3: 107 patients received a single fraction of 7 Gy between 2011 and 2016. Bladder and rectum complications were assessed using RTOG scores and with the objective scores of LENT-SOMA for the vagina.

STATISTICS

the chi-square test.

RESULTS

The mean follow-up of Groups 1, 2 and 3 was 95, 67 and 51 months, respectively. Three patients in Group-1, 2 in Group-2, 1 in Group-3 developed vaginal-cuff relapse (p = 0.68). No differences were found in late toxicity among the three groups.

CONCLUSIONS

One single dose of 7 Gy is safe and effective and may be the best treatment schedule with a similar incidence of vaginal-cuff relapses, complications and patient comfort with less hospital attendance.

Low-Dose Adjuvant Cylinder Brachytherapy for Endometrioid Endometrial Cancer

PURPOSE

Our purpose was to evaluate outcomes and sites of failure for women with early stage endometrial adenocarcinoma treated with adjuvant high-dose-rate (HDR) vaginal brachytherapy (VB) with a low dose scheme.

METHODS AND MATERIALS

Retrospective review identified 318 patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II endometrioid endometrial cancer who received adjuvant HDR VB to a dose of 24 Gray (Gy) in 6 fractions from 2005 to 2017. Patients with <6 months follow-up were excluded. Dose was prescribed to cylinder surface and computerized tomography (CT) imaging was performed before each fraction to assess cylinder placement. Rates of vaginal relapse (VR), pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were calculated by Kaplan-Meier method. Univariate analysis was performed by log rank test or Cox proportional hazards. Pretreatment CT images were analyzed for patients with VR.

RESULTS

Median follow-up was 42 months for 243 patients. The 3-year rates of VR, pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were 1.9%, 1.5%, 4.3%, 94.1%, and 98.9%, respectively. The 3-year VR rates by Gynecologic Oncology (GOG)-99 risk groups were 0%, 1.4%, and 3.2% for low risk, low-intermediate risk, and high-intermediate risk (HIR) disease (P = .5). By Post-operative Radiation Therapy in Endometrial Carcinoma (PORTEC) risk stratification, 3-year VR rate was 1.3% for HIR disease. On review of pretreatment CT images of the 6 patients with VR, 3 patients had relapse at the introitus outside of the treated vaginal length, and 3 had in-field recurrence at the vaginal apex. Higher body mass index (BMI) was associated with VR, with a 14% increase in risk per BMI unit (kg/m², P = .02). There were no reported grade 2 GI or any grade 3 toxicities.

CONCLUSIONS

Adjuvant HDR VB with a low-dose regimen results in excellent clinical outcomes for patients with early stage endometrioid endometrial cancer. Patients with higher BMI may be at increased risk of VR, and additional study is needed to optimize brachytherapy treatment parameters.

Clinical and Dosimetric Implications of Intrafractional Cylinder Movement During Vaginal Cuff Brachytherapy

Introduction To quantify the dosimetric and clinical effects of intrafractional cylinder movement in patients receiving high-dose-rate vaginal cuff brachytherapy (VBT) without a formal immobilization device and the implication of motion on institutional clinical outcomes. Methods From 2013-2018, 119 patients were treated with VBT with no formal immobilization device at a single institution. As a quality assessment study, pre-and post-cylinder brachytherapy kilovoltage (kV) images were acquired for 37 fractions in nine consecutive patients who underwent VBT and clinical care representative of institutional practice standards. The D90 and D90 EqD2 were calculated according to each patient's average intrafractional movement throughout the treatment course. The D2cc for organs-at-risk (OARs) were also re-evaluated following the simulated movements. The survival outcomes and toxicity were recorded from the 119 patients. Toxicity was graded as per Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Results The measured mean ± standard deviation movement was 5.0 mm ± 3.5, with 62% moving caudad. The D90 from each patient's maximum and average movements were lower than the pre-planned doses: 71%, and 89%, respectively. The doses to the OARs were lower than the pre-planned doses. After a median follow-up of 20 months, there were three local recurrences with a median time of 14.5 months (range: 10-31). There were two acute grade 3+ toxicities and one late grade 3+ toxicity. There was a moderate correlation (r = 0.40) between body mass index (BMI) and intrafraction movement with caudad being more common in smaller BMIs (p = 0.0216). Conclusions Intrafractional vaginal cylinder movement without a table fixation device is about 5.0 mm, with the majority of movements moving caudad. While institutional outcomes suggest that local control may not be compromised, consideration of more formal immobilization devices is warranted, especially for those patients with lower BMIs.

Economic impact of decreasing the fraction number in vaginal cuff brachytherapy: A direct cost analysis

PURPOSE

The purpose of this study was to analyze the direct economic impact of two vaginal cuff brachytherapy (VBT) schedules in postoperative endometrial carcinoma (PEC) with similar vaginal control and toxicity results.

MATERIALS AND METHODS

From 2006 to 2015, 397 PEC patients (p) were treated with VBT: mean 40p/year, 67.5% received external beam radiotherapy (EBRT)+VBT and 32.5% exclusive VBT. Schedule 1: 3 fractions (Fr) after EBRT and 6Fr (4-6 Gy/Fr) in exclusive VBT. Schedule 2: 7Gy × 1Fr + EBRT and 6Gy × 3Fr in exclusive VBT. Differential cost analysis of the two schedules was retrospectively performed. The direct costs in each schedule were (1) Personnel: radiotherapy technicians, nurses, radiation oncologists, medical physicists, administrative personnel, orderlies; time dedicated by each professional during CT planning acquisitions and delineation of vagina/organs at risk, dosimetric study and evaluation, autoradiography, procedure reporting time during/after treatment, removal of bladder/rectal tubes and applicators, material cleaning and transportation for sterilization; (2) Health care material (gels, gauzes, gloves, etc); (3) Equipment (time equipment used). The differential between the two schedules was estimated. Indirect costs and evaluation of quality of life-adjusted costs were not considered.

RESULTS

The overall reduction in the number of Fr per year in Schedule 2 was 93. Cost savings included treatment time per year: 4,185 min (70 h); personnel: 221€ ($246)/p in EBRT + VBT and 331€ ($368)/p in exclusive VBT; and health care material and equipment: 40€ ($44.5)/p in EBRT + VBT and 90€ ($100.2)/p in exclusive VBT. The overall savings per patient was 261€ ($295) in combined treatment and 421€ ($475.7) in exclusive VBT. The total savings per year with Schedule 2 in 40p was 12,503€ ($13,915.8).

CONCLUSIONS

A 41% reduction in the fractions number in VBT for PEC allowed economic savings of 261€ ($290.5)/p in combined treatment and 421€ ($475.7)/p in exclusive VBT. Other benefits include patient comfort and fewer treatment visits.

Modern Brachytherapy

Brachytherapy involves the placement of radioactive sources within or very close to the tumor. This placement allows a high dose of radiotherapy to be delivered to the tumor while sparing the surrounding normal tissue. The delivery of brachytherapy has changed markedly over the years, with newer radioactive sources making delivery safer, image guidance techniques allowing more accurate placement of sources, and advanced planning systems allowing brachytherapy to be truly adaptive. This article explores the most modern techniques and current uses of brachytherapy in the treatment of gynecological, prostate, breast, rectal, and skin cancers.

The vaginal cylinder: Misunderstood, misused, or trivial? An in-depth dosimetric and multiinstitutional outcome investigation

PURPOSE

The purpose of the study was to investigate the impact on dose distribution and radiobiological metrics of common high-dose-rate vaginal brachytherapy treatment parameters and to analyze multiinstitutional data for clinically significant impact on outcomes in early-stage endometrial cancer.

METHODS AND MATERIALS

Treatment plans were created for all combinations of prescription parameters and used to quantify the dosimetric impact of each parameter and to estimate the dose delivered using common voxel-integrated radiobiological metrics. A rating system, based on risk grouping from GOG and PORTEC trials, was used to consolidate staging information into a cancer "aggressiveness" measure. Correlations between the rating, toxicity, disease recurrence, and plan parameters were investigated.

RESULTS

When prescribing to 5 mm depth, the variation caused by the diameter was very large across all dose metrics, ranging from 51% to 175% increase with the most divergence in BED_max. For surface prescription, changing the cylinder diameter from 4 cm to 2 cm caused the dose metrics of BED_min, D_min, and gBEUD (a = -3) to increase by 117%, 67%, and 52%, respectively. Prescription to 5-mm depth caused changes across all dose metrics of 260% compared with surface prescription for a 2-cm cylinder. Deeper prescription point (p = 0.005) and longer treatment length (p = 0.01) were correlated with increased stenosis rates. No correlation between recurrence and any plan parameter was found.

CONCLUSIONS

Dramatic differences in dose distributions arise by small variations of plan parameters, with large impact on rates of vaginal stenosis, but no clear relation with local recurrence. To help radiation oncologists interpret the magnitude of these effects for their patients, we created a tool that allows comparison between dose and fractionation parameters.

Radiotherapy practices in postoperative endometrial cancer: A survey of the ABS membership

PURPOSE

This survey aimed to document the current practice patterns of postoperative radiotherapy (RT), including vaginal vault brachytherapy (VVB) and external beam radiotherapy (EBRT), in the management of patients with endometrial cancer.

METHODS AND MATERIALS

A 30-item, multiple choice survey querying RT prescribing practices and planning techniques was distributed electronically to American Brachytherapy Society members in December 2018.

RESULTS

Seventy-five surveys from 62 centers were completed. Eighty-nine percent of respondents practiced within the USA or Canada. Most (79%) respondents indicated a preference for recommending adjuvant VVB alone in FIGO Stage IB, Grade 2 margin and lymphovascular space invasion (LVSI) negative disease. For FIGO Stage IB, Grade 3, LVSI-positive disease, most respondents preferred incorporating EBRT either alone (33%) or with VVB (28%). For IIIC1, margin positive disease, VVB in addition to EBRT was most commonly recommended (75%). When planning adjuvant EBRT, 49% utilized CT simulation with both bladder full and empty. Internal target volume was utilized by 53%. Volumetric modulated arc therapy (53%) or intensity-modulated radiotherapy (19%) were commonly used planning techniques. The most common dose prescription was 45 Gy in 25 fractions (57%). When treating with VVB, 49% determined applicator size at the time of brachytherapy. Sixty-four percent planned treatments based on CT imaging with the applicator in situ and 33% repeated CT imaging before each subsequent fraction. The most common prescription was 21 Gy in three fractions prescribed to 0.5 cm depth (43%).

CONCLUSIONS

This study identified variability in treatment recommendations and in both EBRT and VVB simulation and planning processes in postoperative endometrial cancer.

Do vaginal recurrence rates differ among adjuvant vaginal brachytherapy regimens in early-stage endometrial cancer?

PURPOSE

We sought to retrospectively examine clinical outcomes for three adjuvant vaginal high-dose-rate (HDR) brachytherapy regimens after hysterectomy for early-stage endometrial cancer.

METHODS

Included were women of all ages from two independent hospital systems diagnosed with Stage I-II endometrial cancer of any grade between 2000 and 2016 who underwent hysterectomy followed by adjuvant vaginal cylinder HDR brachytherapy with either 7.0 Gy × 3 fractions prescribed to 0.5 cm vaginal depth, 6.5 Gy × 3 fractions prescribed to 0.5 cm vaginal depth, or 6.0 Gy × 5 fractions prescribed to the vaginal surface. Outcomes included vaginal recurrence (VR), pelvic recurrence, distant recurrence, locoregional recurrence, recurrence-free survival, and overall survival.

RESULTS

Of the 348 women, 45 (13%) received 7.0 Gy × 3 fractions, 259 (74%) received 6.5 Gy × 3 fractions, and 44 (13%) received 6.0 Gy × 5 fractions. Women receiving 5-fraction brachytherapy were more likely to be younger with a higher performance status. At a median follow-up of 4.5 years, VR rates were 2.2%, 0.8%, and 4.5%, respectively. Multivariate analysis revealed no significant differences in the risks for VR among brachytherapy regimens. Risks for VR, pelvic recurrence, distant recurrence, locoregional recurrence, recurrence-free survival, and overall survival did not differ between propensity score-matched five- and 3-fraction brachytherapy cohorts.

CONCLUSIONS

VR rates after hysterectomy and adjuvant vaginal brachytherapy for early-stage endometrial cancer were low and not significantly different by HDR dose fractionation.

Cost in perspective: direct assessment of American market acceptability of Co-60 in gynecologic high-dose-rate brachytherapy and contrast with experience abroad

Purpose

While Ir-192 remains the mainstay isotope for gynecologic high-dose-rate (HDR) brachytherapy in the U.S., Co-60 is used abroad. Co-60 has a longer half-life than Ir-192, which may lead to long-term cost savings; however, its higher energy requires greater shielding. This study analyzes Co-60 acceptability based on a one-time expense of additional shielding and reports the financial experience of Co-60 in Peru’s National Cancer Institute, which uses both isotopes.

Material and methods

A nationwide survey was undertaken assessing physician knowledge of Co-60 and willingness-to-pay (WTP) for additional shielding, assuming a source more cost-effective than Ir-192 was available. With 440 respondents, 280 clinicians were decision-makers and provided WTPs, with results previously reported. After completing a shielding report, we estimated costs for shielding expansion, noting acceptability to decision makers’ WTP. Using activity-based costing, we note the Peruvian fiscal experience.

Results

Shielding estimates ranged from $173,000 to $418,000. The percentage of respondents accepting high-density modular or lead shielding (for union and non-union settings) were 17.5%, 11.4%, 3.9%, and 3.2%, respectively. Shielding acceptance was associated with greater number of radiation oncologists in a respondent’s department but not time in practice or the American Brachytherapy Society membership. Peru’s experience noted cost savings with Co-60 of $52,400 annually.

Conclusions

By comparing the cost of additional shielding for a sample institution’s HDR suite with radiation oncologists’ WTP, this multi-institutional collaboration noted < 20% of clinicians would accept additional shielding. Despite low acceptability in the US, Co-60 demonstrates cost-favorability in Peru and may similarly in other locations.

Does adjuvant concurrent or sequential chemotherapy increase the radiation-related toxicity of vaginal brachytherapy for endometrial cancer patients?

PURPOSE

To compare radiation toxicity in endometrial cancer patients treated with adjuvant vaginal brachytherapy (VBT) vs. VBT with concurrent chemotherapy (CCT) or sequential chemotherapy (SCT) METHODS: We retrospectively analyzed 131 patients with endometrial cancer treated with VBT without external beam radiation therapy. Toxicities were graded according to the Common Terminology Criteria for Adverse Events v4.03. CCT was defined as VBT delivered between the first and last cycle of chemotherapy (CT); SCT was defined as VBT delivered before or after CT.

RESULTS

Median followup was 36 months, with a 3-year survival rate of 88%. Of the 131 patients, 92 were treated with VBT alone, 34 with VBT and CCT, and 5 with VBT and SCT. The most common toxicity was vaginal stricture, with 30 (22.9%) patients affected. The distribution of toxicities was vaginal 28%, urinary 12%, rectal 11%, and fatigue 5%; none greater than Grade 2. Compared with patients treated with VBT alone, the addition of CT did not increase the chance of vaginal stricture formation (p = 0.84). The difference in system-specific toxicities between treatment modalities was not statistically significant.

CONCLUSION

The most common pelvic toxicity from VBT is vaginal stenosis with other toxicities being infrequent and generally Grade 1. The addition of CT in a sequential or concurrent fashion did not increase the rate of pelvic toxicity from VBT alone.

Extended duration of dilator use beyond 1 year may reduce vaginal stenosis after intravaginal high-dose-rate brachytherapy

BACKGROUND

Vaginal dilators (VD) are recommended following vaginal or pelvic radiotherapy for patients with endometrial carcinoma (EC) to prevent vaginal stenosis (VS). The time course of VS is not fully understood and the optimal duration of VD use is unknown.

METHODS

We reviewed 243 stage IA-II EC patients who received adjuvant brachytherapy (BT) at an academic tertiary referral center. Patients were instructed to use their VD three times per week for at least 1-year duration. The primary outcome was development of grade ≥ 1 VS using CTCAEv4 criteria during the follow-up period. The log-rank test and multivariable Cox proportional hazards modeling were used to evaluate the effect of VD use (noncompliance vs. standard compliance [up to 1 year] vs. extended compliance [over 1 year]) on VS.

RESULTS

The median follow-up was 15.2 months over the 5-year study period. At 15 months, the incidence of VS was 38.8% for noncompliant patients, 33.5% for those with standard compliance, and 21.4% for those with extended compliance (median time to grade ≥ 1 VS was 17.5 months, 26.7 months, and not yet reached for these groups, respectively). On multivariable Cox regression analysis, extended compliance remained a significant predictor of reduced VS risk when compared to both noncompliance (HR 0.38, 95% CI 0.18-0.80, p = 0.012) and standard compliance (HR 0.43, 95% CI 0.20-0.89, p = 0.023).

CONCLUSIONS

The risk of VS persists beyond 1 year after BT. Extended VD compliance beyond 1 year may mitigate this risk.

Vaginal cuff brachytherapy in endometrial cancer - a technically easy treatment?

Endometrial cancer (EC) is one of the most common gynecological cancers among women in the developed countries. Vaginal cuff is the main location of relapses after a curative surgical procedure and postoperative radiation therapy have proven to diminish it. Nevertheless, these results have not translated into better survival results. The preeminent place of vaginal cuff brachytherapy (VCB) in the postoperative treatment of high- to intermediate-risk EC was given by the PORTEC-2 trial, which demonstrated a similar reduction in relapses with VCB than with external beam radiotherapy (EBRT), but VCB induced less late toxicity. As a result of this trial, the use of VCB has increased in clinical practice at the expense of EBRT. A majority of the clinical reviews of VCB usually address the risk categories and patient selection but pay little attention to technical aspects of the VCB procedure. Our review aimed to address both aspects. First of all, we described the risk groups, which guide patient selection for VCB in clinical practice. Then, we depicted several technical aspects that might influence dose deposition and toxicity. Bladder distension and rectal distension as well as applicator position or patient position are some of those variables that we reviewed.

Comparative results of three short brachytherapy schedules as exclusive treatment in postoperative endometrial carcinoma

PURPOSE

To compare vaginal control and treatment toxicity of three different high-dose-rate brachytherapy schedules as exclusive treatment in postoperative endometrial carcinoma.

METHODS AND MATERIALS

From 2003 to 2015, three different schedules were used as postoperative treatment for 146 patients (p) with intermediate-risk endometrial carcinoma. Group 1 (41 p): six fractions of 4-6 Gy, 3-4 fractions per week; Group 2 (59 p): four fractions of 5-6 Gy administered daily; Group 3 (46 p): 6 Gy × 3 fractions in three consecutive days. The dose was prescribed at 5 mm of applicator surface using an active treatment length of 2.5 cm. Toxicity scores were evaluated using the Radiation Therapy Oncology Group scores for bladder and rectum and the objective criteria of late effects of normal tissues-subjective, objective, management, analytic for vagina. Statistics used were group descriptions calculating their means, medians, and ranges. Bivariate analysis was evaluated using variance models and χ² tests.

RESULTS

The mean followup was as follows: Group 1: 88 months, Group 2: 75 months, and 41 months in Group 3. No vaginal relapses were found. Late toxicity ≥ G2: rectum: 0 p in the three groups (0%). Bladder: Group 1: 1 p (2.4%), Group 2: 0%, and Group 3: 0%. Vagina: Group 1: 4 p (9.5%); Group 2: 9 p (15.3%); and Group 3:10 p (21.8%). There were no differences in late toxicity among the three groups of patients for rectum (p = 0.83), bladder (p = 0.58), and vagina (p = 0.67); the expected global risk of complications for rectum, bladder, and vagina is 0.8%, 0.8%, and 28.8%, respectively.

CONCLUSIONS

Similar results in vaginal control and complications were achieved with the three schedules. The use of three fractions of 6 Gy administered daily is the best option for patient comfort and convenience and use of resources. Nonetheless, specific studies are needed to demonstrate the best cost-efficacy regime.

External pelvic and vaginal irradiation vs. vaginal irradiation alone as postoperative therapy in women with early stage uterine serous carcinoma: Results of a National Cancer Database analysis

PURPOSE

Adjuvant treatment in early stage uterine serous carcinoma (USC) usually consists of chemotherapy with vaginal brachytherapy (VB), pelvic external beam radiation therapy (EBRT), or combination. We compared survival outcomes across these various radiation treatment modalities using the National Cancer Database.

METHODS AND MATERIALS

The National Cancer Database was queried for adult females with histologically confirmed International Federation of Gynecology and Obstetrics 1988 Stage I-II USC diagnosed from 2003 to 2013 treated definitively with hysterectomy, adjuvant chemotherapy, and radiation therapy. χ² tests were used to assess differences by radiation type (VB, pelvic EBRT, and EBRT + VB) and various clinical variables. Kaplan-Meier and log-rank test methods were used to evaluate survival outcomes. Risk factors related to overall survival were identified by univariate and multivariate analysis.

RESULTS

We identified 1336 patients with USC who met our inclusion criteria. Most patients were treated with VB (66%) compared with EBRT (21%) or combination EBRT + VB (13%). The proportion of patients who received EBRT (including EBRT + VB) was higher for those who did not have a lymph node dissection or with fewer dissected lymph nodes. Patients treated with VB alone had longer 5-year survival rates (84% [95% confidence interval: 80, 90]) than those treated with EBRT (75% [95% confidence interval: 69, 80]) (p < 0.001). On multivariate analysis, the presence of lymphovascular space invasion (hazard ratio, 2.48; p < 0.001) and the absence of a lymph node dissection (hazard ratio, 2.24; p = 0.047) were independent predictors of overall survival.

CONCLUSIONS

This large hospital-based study suggests that VB alone may be sufficient for adjuvant radiation treatment in women with USC treated with adjuvant chemotherapy and who underwent an adequate surgical staging.

American Brachytherapy Task Group Report: Adjuvant vaginal brachytherapy for early-stage endometrial cancer: A comprehensive review

This article aims to review the risk stratification of endometrial cancer, treatment rationale, outcomes, treatment planning, and treatment recommendations of vaginal brachytherapy (VBT) in the postoperative management of endometrial cancer patients. The authors performed a thorough review of the literature and reference pertinent articles pertaining to the aims of this review. Adjuvant VBT for early-stage endometrial cancer patients results in very low rates of vaginal recurrence (0-3.1%) with low rates of late toxicity which are primarily vaginal in nature. Post-Operative Radiation Therapy in Endometrial Cancer 2 (PORTEC-2) supports that VBT results in noninferior rates of vaginal recurrence compared to external beam radiotherapy for the treatment of high-intermediate risk patients. VBT as a boost after external beam radiotherapy, in combination with chemotherapy, and for high-risk histologies have shown excellent results as well though randomized data do not exist supporting VBT boost. There are many different applicators, dose-fractionation schedules, and treatment planning techniques which all result in favorable clinical outcomes and low rates of toxicity. Recommendations have been published by the American Brachytherapy Society and the American Society of Radiation Oncology to help guide practitioners in the use of VBT. Data support that patients and physicians prefer joint decision making regarding the use of VBT, and patients often desire additional treatment for a marginal benefit in risk of recurrence. Discussions regarding adjuvant therapy for endometrial cancer are best performed in a multidisciplinary setting, and patients should be counseled properly regarding the risks and benefits of adjuvant therapy.

A new short daily brachytherapy schedule in postoperative endometrial carcinoma. Preliminary results

PURPOSE

To evaluate the preliminary results of vaginal-cuff relapses (VCR) and complications of a short brachytherapy (BT) schedule in postoperative endometrial carcinoma.

METHODS AND MATERIALS

From September 2011 to December 2014, 102 patients were treated with postoperative BT for endometrial carcinoma. Seventy-four patients received a single 7 Gy dose after external beam irradiation (Group 1), and 28 intermediate-risk patients received three daily fractions of 6 Gy (Group 2). The dose was prescribed at 5 mm from the applicator surface. Toxicity was prospectively evaluated after the objective late effects of normal tissues-subjective, objective, management, analytic scores for vagina and RTOG scores for rectum and bladder.

STATISTICS

χ² and Student's t tests.

RESULTS

The mean followup was 28.85 months (9.6-58.5) in Group 1 and 31.19 months (7.7-62.3) in Group 2. No VCR was found during followup. Late toxicity: vagina toxicity was developed in 24.32% of the patients in Group 1 (G1-G2) and in 21.4% in Group 2 (G1-G2 but 1 G3). Rectal toxicity appeared in only 2.7% of patients in Group 1 (G1). Neither Group 1 nor Group 2 presented late bladder toxicity. No differences were found in late toxicity between Groups 1 and 2.

CONCLUSIONS

The present short BT schedule was safe in relation to VCR and late toxicity for the followup period studied. These results are similar to those of two larger previous schedules performed in our center in relation to the same point of followup.

Trends in the utilization of adjuvant vaginal brachytherapy in women with early-stage endometrial carcinoma: Results of an updated period analysis of SEER data

PURPOSE

Adjuvant vaginal brachytherapy (VB) is a well-established and effective radiation treatment modality in women with early-stage endometrial carcinoma. We sought to evaluate and update published trends in the utilization of VB vs. other radiation therapy modalities (pelvic external beam radiation therapy (EBRT) or the combination of VB and pelvic EBRT using the National Cancer Institute's Surveillance, Epidemiology, and End Results database.

METHODS AND MATERIALS

The Surveillance, Epidemiology, and End Results database was queried for adult females with histologically confirmed International Federation of Gynecology and Obstetrics 1988 Stage I-II endometrial carcinoma diagnosed from 1995 to 2012 and treated definitively with hysterectomy and adjuvant radiation therapy. Chi-square tests were used to assess differences by radiation type (VB, EBRT, and VB + EBRT) and various demographic and clinical variables.

RESULTS

We identified 15,201 patients that met inclusion criteria. There was a significant overall increase in the use of VB was observed from 17.1% in 1995-2000 compared to 57.1% in 2007-2012 (p < 0.0001). Similarly, there was a proportional decrease in the use of EBRT from 54.0% to 25.5% (p < 0.0001) as well as in the use of VB + EBRT from 28.9% to 17.4% during the same period (p < 0.0001). The observed increase in utilization of VB was not limited to any variables (age, race, histological type, International Federation of Gynecology and Obstetrics stage, and the status of lymph node dissection [yes or no]) or the number of dissected lymph nodes.

CONCLUSIONS

In this large national database set, there continues to be an increasing trend for the use of VB in the adjuvant setting in women with early-stage endometrial carcinoma.